Complexity analysis of resting state magnetoencephalography activity in traumatic brain injury patients.

Diagnosis of mild traumatic brain injuries (TBIs) has been difficult because of the absence of obvious focal brain lesions, using conventional computed tomography (CT) or magnetic resonance imaging (MRI) scans, in a large percentage of TBIs. One useful measure that can characterize potential tissue and neural network damage objectively is Lempel-Ziv complexity (LZC) applied to magnetoencephalography (MEG) signals. LZC is a model-independent estimator of system complexity that estimates the number of different patterns in a sequence.

Cortical dysplasia: zones of epileptogenesis.

Cortical dysplasia describes a wide range of cerebral cortex structural anomalies and is a condition attributed to multiple etiologies including disruption in the migration of the maturing neurons, disturbance of the process of programmed cell death in the fetal brain, and even noxious environmental influence. Cortical dysplasia can be focal or diffuse and the insult depends more on the timing of the defect in neural development and to a lesser extent the cause. Identification of cortical dysplasia can be done using high resolution magnetic resonance imaging (MRI), histological examination of affected tissue, and EEG.